Object, Instrument, Technology

The Fourier analyzer, which was called by Rudolph Koenig an “Analyzer of the timbre of sounds”, is a large device (about 36 inches tall) for simultaneously observing several components of a sound.

Object, Instrument, Technology

The Case Collection of Physics Instruments (CCPI) has several dozen forks mounted on resonance boxes (see Fig. 1).

Object, Instrument, Technology

William Stern invented the tone variator in 1897 to study human sensitivity to changes in pitch, going beyond the traditional psychological research of studying the sensitivity to differences in discrete tones. The instrument consists of an adjustable brass resonator (see Helmholtz resonator for more information), which is supplied with a constant flow of air across an opening at the top.

Object, Instrument, Technology

Helmholtz described in his 1862 [sic] book, On the Sensations of Tone, an apparatus able to pick out specific frequencies from a sound. The Helmholtz resonator, as it is now called, consists of a rigid container of a known volume, nearly spherical in shape, with a small neck and hole in one end and a larger hole in the other end to admit the sound.

Object, Instrument, Technology

See also Helmholtz resonator

Picture: Max Planck Institute for the History of Science

Object, Instrument, Technology

“Kontinuirlicher Resonatoren-Apparat nach Schaefer made by E. Zimmermann, Leipzig, Berlin

Picture: Max Planck Institute for the History of Science

Object, Instrument, Technology

„In 1862, the German scientist Herman Helmholtz invented another important acoustic instrument, the double siren. The new instrument combined two Dove Sirens, which were positioned to face each other and coupled on the same shaft. Both sirens were also connected to the same air supply, which made it possible to produce a variety of frequencies, all of which would slide up or down the scale as the air pressure was increased or decreased.

Video
2012. “Introduction To Resonance With Artifacts From The National Museum Of American History”. Smithsonian National Museum of American History. https://www.youtube.com/watch?v=Rn93ure-Fa8.
Object, Instrument, Technology

This is a set of 16 Helmholtz resonators. Made from sections of brass that were spun on a lathe, they are wonderfully light and easy to hold. Helmholtz designed them to demonstrate his theory that all vowel and musical sounds are composed of combinations of simple, pure notes (Helmholtz’s “Theory of Timbre”). He correctly observed that musical sounds, particularly the higher tones, are often perceived as a single mass of sound.

Object, Instrument, Technology

In the second quarter of the 19th century, the French scientist Felix Savart invented this apparatus to demonstrate resonance. It consists of a “bell” (or brass bowl) and a moveable wooden resonator. In the demonstration the bell was activated by being either bowed or struck. As the bell rang, its’ loudness could be increased or diminished by moving the resonator closer or further away. When the sound of the bell became barely audible an effective demonstration was to quickly move the resonator right next to it. The increase in loudness – the 'resonant effect' – was striking.